Chapter 1: Introduction

In life as well as the sciences, we frequently meet situations where there is a lack of complete clarity on the nature of the events taking place. The problem may be due to the interpretation of the information presented or be purely conceptual in nature. A prolonged debate is usually avoided when the observer agrees to accept the established view. Such a decision, however, denies the opportunity for further discussion or investigation of the subject. The following lists some personal examples of such situations relating to well-known physical observations at both the microscopic and the cosmological scales.

I was walking down the stairwell of the Physics Department building—a routine I had repeated hundreds of times before—but, this time, I decided to stop at the landing and look at the curious picture that had been hanging on the wall there all these years.

It was a small, ordinary-looking black-and-white picture in a brown frame. I took a closer look and found that it showed an array of closely packed gray dots on a dark background.

By this time a colleague had joined me at the scene and explained that it was a high-resolution scanning electron microscope (SEM) image of a silicon surface. The gray dots, he said, were individual silicon atoms that made up the crystalline structure of the solid material. This was my first view of such imagery and I was awestruck with the experience of actually viewing pictures of individual atoms for the first time.

Many years later, during my short stint in the Physics Department of Monash University in Australia, I had the opportunity to use an SEM and experiment with an atomic force microscope (AFM) for my experimental work. About the same time, I happened to come across a PhD dissertation by a student of condensed matter physics, who had been charged with undertaking similar experiments for his work. However, although he used the results of high-resolution microscopy, the introduction to his thesis showed that he was not at all convinced that the “pictures” of atoms he saw were real. He argued strongly that what we saw through the instrument really depended on how we interpreted the information in the image and this depended on the personal judgement of the viewer.

Although it was clear that the student's supervisor would not have been at all happy with such a remark, can we really dismiss the disgruntled murmurings of the student researcher as irrelevant? Upon reflection, the student had merely pointed out that the nature of the physical reality being examined depended on the way we interpreted the results of a measurement carried out by an instrument. What should an appropriate response be to the student's observation?

I was visiting New Delhi when the first detection of gravitational waves was announced. They were detected simultaneously by two detectors situated at different locations. The event made headline news globally.

According to accepted astrophysics, the waves were caused by the collision of two black holes millions of light years away. The distances involved meant that what we had experienced here on Earth only recently had happened far away and in the dim past of our astronomical history. And it reminded us that the only way we could learn of this happening was through the use of instruments used in experiments performed in the here and now on Earth. It makes one realize that it is not possible to directly experience things beyond our normal (human) reach, or that happen in the present at other locations. As in the case of investigating the microscopic world with high-powered microscopes, we must necessarily depend on instruments to carry out this task for us. These instruments act as extensions to our senses, and we have to contend with the results of such measurements to provide us with the only evidence of the reality of events at these humanly unreachable scales.

We are essentially trapped in the present and here where we exist in the space–time continuum. It is not a very reassuring situation, but we need to understand it as well as we can if we are to make any headway in understanding the new ideas emerging in the world of science today.

I sat in my nuclear physics lecture listening to my lecturer introducing the salient features of beta decay theory and the neutrino hypothesis. My lasting memory of that lecture is my steadfast reluctance to accept the words of the lecturer as he described the discovery of the neutrino in the search of an explanation for the continuous beta decay spectrum. My whole being was reacting to the assertion that an elusive new particle was being proposed as the answer to the riddle of the experimentally observed continuous beta spectrum. Was it not obvious that the answer lay in the falsification of the conservation laws of energy and momentum? After all, we were looking at experimental evidence and, as physicists, we were supposed to accept this as evidence of reality.

However, considerable time had gone by since the first proposal of the neutrino in 1930 and its detection in 1956 to the present, and the idea of the neutrino as a particle had been firmly established in the minds of physicists and lay persons alike. Today the detection of the neutrino (and its oscillations) is carried out on a routine basis (see, e.g., the IceCube experiment in Antarctica https://icecube.wisc.edu, accessed 14 April 2020), and it would be sacrilege to deny its existence! And yet the question still remains—how do we fit this historical evolution of a physical concept into a bigger picture?

What was notable about the discovery of the neutrino was the process by which it became acceptable. We will consider this process at greater length later.

It is well known that there are differing views among thinkers about the nature of (physical) reality. We have, for instance, the positivists who claim that physical reality is absolute and exists regardless of the presence of humans, and the relativists who believe that it is purely subjective.

Although their views may differ widely, all thinkers will agree that we need concepts to think and that concepts exist in our minds. They are therefore subjective entities. A question that arises naturally is whether there is any relationship between the subjective and the objective.

The positivist will perhaps be quick to point out that physical reality is that which can be verified and measured through physical experiments, while the subjective cannot be verified in this way. And they will be essentially correct. We will later be asking whether the subjective can ever become objective. Is there a process by which a purely subjective entity can acquire objective physical reality? We will consider situations where this proposition may not appear as far-fetched as it first sounds.

Our theories of physics have undergone rapid evolution and transformation over the last few decades. This has occurred at both the microscopic and the cosmological scales. There has been a merger of theories at both scales to generate new ideas. This has provided new perspectives on physical reality, leading to a plethora of new theories, sometimes with surprisingly brilliant successes.

How do these new theories relate to older concepts and theories? To understand recent developments better, there is a need to examine the nature of physical theories upon which these newer ideas are based. As we will see later, these theories of physics may be categorized into the phenomenological (or ideal), the fundamental, and the historical. Over the decades, the nature of the theory in vogue has changed from the phenomenological/ideal (infinite and timeless universe) to a historical universe with a finite size and an identifiable beginning (the big bang theory). Theories have been concatenated, for instance the joining of quantum field theory (QFT) of the vacuum with an outcome of General Theory of Relativity (GTR) of a black hole to produce interesting results (e.g., Hawking radiation). The question that arises naturally is whether this type of gross concatenation is justified. Are there any requirements that such joining of diverse theories must fulfill?

The examples in Sec. 1.3 are hopefully sufficient in themselves to reveal that there are several issues with how we conceive our physical world today, and they point to the need to re-examine the conceptual basis of our thinking to obtain a better understanding of developments in physics (and human thought in general). Before we launch into this task in the chapters that follow, it is possible that there may still be elements of lingering skepticism amongst some regarding the importance of concepts and conceptualization.

The best way to remove any such doubt is through an example. And an excellent example is provided in the work of Albert Einstein on his road to the establishment of the GTR. It is illustrative to see how Einstein used his powers of conceptualization to arrive at his first and second forms of the GTR, and followed this with similar feats of the imagination in the development of the final form of the GTR in 1916.

Einstein had worked out the Special Theory of Relativity (STR) in 1905, but it took him another ten years to come up with a satisfactory framework for a General Theory of Relativity. This was obviously not a simple task. To start earnestly on the task of discovering the new form of the laws of physics and nature, as epitomized by the law of gravitation, Einstein was confronted with a seemingly impossible task—how does one generalize the Special Principle of Relativity on which STR is based to a General Principle of Relativity upon which a GTR would be based. This proved to be a more difficult task than originally envisaged. So how did Einstein do it?

Box 1.1, which shows the thinking he used and the conceptual strategies he deployed to get there, demonstrates how meticulous conceptualization is absolutely vital in the formulation of new theories of any significance (Einstein, 1961).

As the box shows, Einstein used several conceptual techniques in arriving at his final result. These included (but were not limited to) the following:

1. Reinterpreting the equivalence of inertial and gravitational masses by assigning new significance to the two types of masses (a “degeneracy of concepts” approach).

2. Generalization from specific examples to general principles on several occasions:

   • The gravitational field that appears in the cage experiment is equivalent to an acceleration field caused by any force as measured from an external non-accelerated reference frame.

   • The effect of a gravitational field on the path of a light beam in the specific cage experiment implies that light is bent in any gravitational field.

   • Measurements of time and length on a rotating disc show that time measurements will be affected, and the geometry of the space would become non-Euclidean in any arbitrary gravitational field.

   • Measurements of lengths in the specific example of a differentially heated marble slab demonstrate that it is not possible to use Cartesian coordinates to characterize points in any non-Euclidean space–time continuum.

3. Perhaps the most important conceptual device that Einstein used was what may be termed a “Declaration of preferred hypothesis.” As the name implies, this was the statement of a physical principle that Einstein preferred over other similar principles (which he believed were restrictive).

   Despite the obvious experimental evidence that the laws of physics (or mechanics at least) do not have the same form in frames with non-uniform motion, he argued that the contrary should be true, and stated his first form of the Principle of General Relativity (GPR). Later, he asserted his Principle of General Covariance, which formed the basis for the elucidation of the Einstein Field Equations.

He used the analogy of the gas cooker to try to justify the declaration of his GPR. The validity of his argument may be debated, but we will not go into a protracted philosophical argument here to either defend or oppose his proposition. The important point was that he stuck to his guns and, as a result, eventually developed the final form of the General Principle of Relativity. Once this feat was achieved, his (forced declaration of the) Principle of General Covariance for all laws of physics and especially of the law of gravitation (i.e., the Einstein Field Equations) was an easier task.

What drove Einstein to assert the GPR so firmly? Or what gave him the conviction and the courage to do so?

While he may not have stated this in words, it is clear that Einstein's compelling urge to generalize the invariance of physical laws from non-accelerated frames only to any accelerated frame arose form a personal conviction of the central role of symmetry in the elucidation of the behavior of the physical world. Others have been driven by similar considerations, both before and well after Einstein (notable examples being the discovery of the anti-particle, and the work of Gell-Mann and later workers in high energy physics). Indeed, this consideration is no stranger to us ordinary mortals, as we often cite symmetry as partial support for our arguments in the study of physics, as well as in the elaboration of other situations in life.

The really interesting question about the concept of symmetry is where this idea comes from in the first place. The property of symmetry is often associated with the vague concept of nature. What, indeed, is nature, and could this possibly be the source of symmetry in the universe? The last chapters of this book take a bold stance on addressing this question.

This book begins with a critical look at concepts and the role they play in our understanding of the physical (and social) worlds on the one hand, and what they reveal about our theoretical and imagined worlds of mathematics, fantasy, and other realms on the other.

Part II of the book focuses on the physical world, and takes a close look at the main concepts and theories upon which our present understanding of physics is based. It discusses how these concepts have evolved over time, and how certain “newer” concepts have taken precedence over older ones. It points out, however, that the older concepts are not to be regarded as a spent force, as they may yet produce useful insights [in the form, for instance, of the proposed Fundamental Energy-Mass Transformation (FEMT) model] into the present unanswered questions of physics.

The role of planning and developing experiments is just as critical to the experimental verification of theory as are the experimental results. The observer plays a vital role in verifying that results are real. The reader is reminded that the primary interest of the physicist is to understand physical reality. It is the experimental physicist who furnishes this role in the final instance.

It can be argued that the role of the human (observer) is central to both the development of physics and the formulation of theories and constructs in the other “worlds” mentioned in Part I. Part II goes on to show how history, the design of experiments in physics, and the implementation of the experiments all make their own indispensable contributions to the final form of what we perceive as the new physical reality.

Part III discusses issues with current theories of physics that have yet to be addressed. It stresses the need for an expanded conceptual set to construct a new conceptual framework for these issues. It ends by proposing some of the requirements that this new framework must satisfy.